Association between trace elements and preeclampsia: A retrospective cohort study.

BACKGROUND: Preeclampsia is the main cause of maternal and perinatal death. Multiple studies suggest that trace elements were associated with preeclampsia, but the results varied, and less known about early or mid-term pregnancy of trace elements and preeclampsia. We aim to explore the association between mid-term pregnancy trace elements levels and preeclampsia. METHODS: The retrospective cohort study was consecutively conducted in Foshan Fosun Chancheng Hospital, Guangdong Province, China, from August 1, 2019, to November 30, 2019. Trace elements are derived from the laboratory data system, measured in maternal whole blood during 12-27 (+6) weeks of pregnancy by flame atomic absorption spectrometer method. Preeclampsia diagnosis and covariance were ascertained from the electronic medical records system. We used multivariable logical regression to estimate odds ratios (OR) and 95% CIs. RESULTS: A total of 2186 participants were included in this study, and 59 (2.70%) women developed preeclampsia. After multivariable adjustment, the OR of Mg levels for preeclampsia was 0.35 (95%CI:0.06,2.20). The fifth quintiles of Mg were associated with 0.29 (95% CI：0.10,0.85) times lower risk of preeclampsia compared with the first quintile, with a dose-response trend (P for trend = 0.056). Per 1 µmol/L increment in Cu was associated with 11% lower risk of preeclampsia (OR=0.89; 95% CI, 0.78,1.02). Compared with the first quintile, the second, third，fourth，fifth quintile of Cu was associated with a odd ratio of 0.12 (95% CI:0.03,0.43),0.67 (95% CI:0.30,1.48),0.33 (95% CI:0.15,0.76) and 0.26 (95% CI:0.10,0.66),respectively. Null associations were observed for Zn, Fe, Ca. CONCLUSIONS: Higher blood Mg and Cu levels in mid-term pregnancy were associated with lower preeclampsia risk.

Association of blood lead levels with preeclampsia: A cohort study in China.

BACKGROUND: Preeclampsia is the main cause of maternal and perinatal death, especially in developing countries. Multiple studies suggest that blood lead levels in pregnancy are a risk factor for preeclampsia, even with low levels of blood lead. But less knows the dose-effect relationship of preeclampsia in low blood lead levels. OBJECTIVES: This study aims to assess the association between blood lead levels and preeclampsia and to explore its dose-effect relationship between low blood lead levels and preeclampsia. METHODS: The retrospective cohort study was consecutively conducted in a comprehensive tertiary hospital in Foshan city of Guangdong Province, China, from August 1, 2019, to November 30, 2019. Blood lead levels were measured in maternal whole blood in 12-27 (+6) weeks of pregnancy, using atomic absorption spectrometer. Preeclampsia diagnosis was ascertained from the electronic medical records system. The risk of preeclampsia was estimated by multivariable logical regression analysis, and a two-stage linear regression model was established to find out the dose-effect. RESULTS: A total of 2174 people were included in this study, and 59 (2.7%) women developed preeclampsia. The dose-effect analysis revealed a non-linear association between blood lead levels and the risk of preeclampsia, with a cut-off point at 4.2 µg/dl. When blood lead levels were over 4.2 µg/dl, the risk of preeclampsia increased significantly with an increase in blood lead levels (OR = 2.05, 95%CI: 1.50, 2.81). In the multivariate regression models, per 1 µg/dl increment in blood lead levels was associated with 43% higher risk of developing preeclampsia (OR = 1.43,95%CI:1.17,1.74). Moreover, the association between blood lead levels and preeclampsia was stable in different subgroups. CONCLUSIONS: Low levels of lead exposure had a dose-effect relationship of preeclampsia, with a cut-off point at 4.2 µg/dl. Blood lead levels had a non-linear association with preeclampsia. When the blood lead levels were higher than 4.2 µg/dl, the risk of preeclampsia increases by 105% for every 1 µg/dl increase in blood lead levels.

Low-density lipoprotein-coupled micelles with reduction and pH dual sensitivity for intelligent co-delivery of paclitaxel and siRNA to breast tumor.

Multidrug resistance (MDR) is a major obstacle for the clinical therapy of malignant human cancers. The discovery of RNA interference provides efficient gene silencing within tumor cells for reversing MDR. In this study, a new "binary polymer" low-density lipoprotein-N-succinyl chitosan-cystamine-urocanic acid (LDL-NSC-SS-UA) with dual pH/redox sensitivity and targeting effect was synthesized for the co-delivery of breast cancer resistance protein small interfering RNA (siRNA) and paclitaxel (PTX). In vivo, the co-delivering micelles can accumulate in tumor tissue via the enhanced permeability and retention effect and the specific recognition and combination of LDL and LDL receptor, which is overexpressed on the surface of tumor cell membranes. The siRNA-PTX-loaded micelles inhibited gene and drug release under physiological conditions while promoting fast release in an acid microenvironment or in the presence of glutathione. The micelles escaped from the lysosome through the proton sponge effect. Additionally, the micelles exhibited superior antitumor activity and downregulated the protein and mRNA expression levels of breast cancer resistance protein in MCF-7/Taxol cells. The biodistribution and antitumor studies proved that the siRNA-PTX-loaded micelles possessed prolonged circulation time with a remarkable tumor-targeting effect and effectively inhibited tumor growth. Therefore, the novel dual pH/redox-sensitive polymers co-delivering siRNA and PTX with excellent biocompatibility and effective reversal of MDR demonstrate a considerable potential in cancer therapy.

Binary-copolymer system base on low-density lipoprotein-coupled N-succinyl chitosan lipoic acid micelles for co-delivery MDR1 siRNA and paclitaxel, enhances antitumor effects via reducing drug.

The development of effective and stable carriers of small interfering RNA (siRNA) is important for treating cancer with multidrug resistance (MDR). We developed a new gene and drug co-delivery system and checked its characteristics. Low-density lipoprotein (LDL) was coupled with N-succinyl chitosan (NSC) Lipoic acid (LA) micelles and co-delivered MDR1 siRNA and paclitaxel (PTX-siRNA/LDL-NSC-LA) to enhance antitumor effects by silencing the MDR gene of tumors (Li et al., Adv Mater 2014;26:8217-8224). In our study, we developed a new type of containing paclitaxel-loaded micelles and siRNA-loaded LDL nanoparticle. This "binary polymer" is pH and reduction dual-sensitive core-crosslinked micelles. PTX-siRNA/LDL-NSC-LA had an average particle size of (171.6 ± 6.42) nm, entrapment efficiency of (93.92 ± 1.06) %, and drug-loading amount of (12.35% ± 0.87) %. In vitro, MCF-7 cells, high expressed LDL receptor, were more sensitive to this delivery system than to taxol® and cell activity was inhibited significantly. Fluorescence microscopy showed that PTX-siRNA/LDL-NSC-LA was uptaken very conveniently and played a key role in antitumor activity. PTX-siRNA/LDL-NSC-LA protected the siRNA from degradation by macrophage phagocytosis and evidently down-regulated the level of mdr1 mRNA as well as the expression of P-gp. We tested the target ability of PTX-siRNA/LDL-NSC-LA in vivo in tumor-bearing nude mice. Results showed that this system could directly deliver siRNA and PTX to cancer cells. Thus, new co-delivering siRNA and antitumor drugs should be explored for solving MDR in cancer. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1114-1125, 2017.

N-Succinyl-chitosan nanoparticles coupled with low-density lipoprotein for targeted osthole-loaded delivery to low-density lipoprotein receptor-rich tumors.

N-Succinyl-chitosan (NSC) was synthesized and NSC nanoparticles (NPs) with loaded osthole (Ost) (Ost/NSC-NPs) were prepared by emulsion solvent diffusion. Subsequently, low-density lipoprotein (LDL)-mediated NSC-NPs with loaded Ost (Ost/LDL-NSC-NPs) were obtained by coupling LDL with Ost/NSC-NPs through amide linkage. The average particle size of Ost/NSC-NPs was approximately 145 nm, the entrapment efficiency was 78.28%±2.06%, and the drug-loading amount was 18.09%±0.17%. The release of Ost from Ost/NSC-NPs in vitro showed a more evident sustained effect than the native material. The half maximal inhibitory concentration of Ost/LDL-NSC-NPs was only 16.23% that of the free Ost at 24 hours in HepG2 cells. Ost inhibited HepG2 cell proliferation by arresting cells in the synthesis phase of the cell cycle and by triggering apoptosis. Cellular uptake and subcellular localization in vitro and near-infrared fluorescence real-time imaging in vivo showed that Ost/LDL-NSC-NPs had high targeting efficacy. Therefore, LDL-NSC-NPs are a promising system for targeted Ost delivery to liver tumor.

Low-density lipoprotein-coupled N-succinyl chitosan nanoparticles co-delivering siRNA and doxorubicin for hepatocyte-targeted therapy.

Developing safe and effective carriers of small interference RNA (siRNA) is a significant demand for the systemic delivery of siRNA. In this study, low-density lipoprotein (LDL) was isolated from human plasma and loaded with cholesterol-conjugated siRNA to silence the multidrug resistant gene of tumors. Chol-siRNA/LDL-coupled N-succinyl chitosan nanoparticles loaded with doxorubicin (Dox-siRNA/LDL-SCS-NPs) were then prepared and characterised. The Dox-siRNA/LDL-SCS-NPs had average particle size of 206.4 ± 9.2 nm, entrapment efficiency of 71.06% ± 1.42%, and drug-loading amount of 12.35% ± 0.87%. In vitro antitumor activity revealed that cell growth was significantly inhibited. The accumulation of Dox by fluorescence microscopy and flow cytometry showed that LDL-coupled nanoparticles were more easily taken up than Dox-SCS-NPs. Results of confocal microscopy and reverse transcription-PCR revealed the highly efficient uptake of siRNA and the decrease in mdr1 mRNA expression. LDL-coupled nanoparticles protected siRNA from macrophage phagocytosis by dynamic observation using live cell station. In vivo tumor-targeting suggested that Cy7-labelled Dox-LDL-SCS-NPs were markedly accumulated in an analyzed in situ liver tumor model. Results indicated that LDL-SCS-NPs were effective tumor-targeting vectors and that the preparation form may provide a new strategy for co-delivering siRNA and antitumor drugs.

Novel self-assembled micelles based on palmitoyl-trimethyl-chitosan for efficient delivery of harmine to liver cancer.

BACKGROUND: Polymeric micelles is a safe and effective delivery system, which belong to the targeted delivery system (TDS). An anticancer drug, harmine(HM) is a hydrophobic drug with much adverse effects when used for treatment of liver cancer. Chitosan (CS) is a polysaccharide and can be modified to be an amphiphilic polmer which could self-assemble into micelles and be applied for delivery of hydrophobic drugs. OBJECTIVES: To synthesize three kinds of novel biodegradable polymers, designated as palmitoyl-trimethyl-CS (TPCS)1, TPCS2 and Lac-TPCS2, and investigate their efficiency and mechanism of delivery HM to liver tumors in vitro and in viro. RESULTS: The self-assembled micelles presented satisfactory particle size (∼ 200 nm) and drug release characteristics in vitro. It's proved that Lac-TPCS2/HM may enter HepG2 cell through endocytosis. Antitumor experiments in vivo revealed that Lac-TPCS2/HM could significantly inhibit tumor growth and extend the lifetime of mice bearing H22 tumors after intravenous administration. Subsequently in vivo near-infrared fluorescence imaging results demonstrated a satisfactory liver tumor-targeting effect of Lac-TPCS2/HM. CONCLUSION: Three novel polymers hold great potential in the development of nanomedicine for treatment of liver tumors, in particular Lac-TPCS2 exhibits the greatest antitumor potential through active target effect.

Synthesis and characterization of low-toxicity N-caprinoyl-N-trimethyl chitosan as self-assembled micelles carriers for osthole.

Novel amphiphilic chitosan derivatives (N-caprinoyl-N-trimethyl chitosan [CA-TMC]) were synthesized by grafting the hydrophobic moiety caprinoyl (CA) and hydrophilic moiety trimethyl chitosan to prepare carriers with good compatibility for poorly soluble drugs. Based on self-assembly, CA-TMC can form micelles with sizes ranging from 136 nm to 212 nm. The critical aggregation concentration increased from 0.6 mg • L(-1) to 88 mg • L(-1) with decrease in the degree of CA substitution. Osthole (OST) could be easily encapsulated into the CA-TMC micelles. The highest entrapment efficiency and drug loading of OST-loaded CA-TMC micelles(OST/CA-TMC) were 79.1% and 19.1%, respectively. The antitumor efficacy results show that OST/CA-TMC micelles have significant antitumor activity on Hela and MCF-7 cells, with a 50% of cell growth inhibition (IC50) of 35.8 and 46.7 µg. mL(-1), respectively. Cell apoptosis was the main effect on cell death of Hela and MCF-7 cells after OST administration. The blank micelles did not affect apoptosis or cell death of Hela and MCF-7 cells. The fluorescence imaging results indicated that OST/CA-TMC micelles could be easily uptaken by Hela and MCF-7 cells and could localize in the cell nuclei. These findings suggest that CA-TMC micelles are promising carriers for OST delivery in cancer therapy.

Application of the central composite design to optimize the preparation of novel micelles of harmine.

Lactose-palmitoyl-trimethyl-chitosan (Lac-TPCS), a novel amphipathic self-assembled polymer, was synthesized for administration of insoluble drugs to reduce their adverse effects. The central composite design was used to study the preparation technique of harmine (HM)-loaded self-assembled micelles based on Lac-TPCS (Lac-TPCS/HM). Three preparation methods and single factors were screened, including solvent type, HM amount, hydration volume, and temperature. The optimal preparation technique was identified after investigating the influence of two independent factors, namely, HM amount and hydration volume, on four indexes, ie, encapsulation efficiency (EE), drug-loading amount (LD), particle size, and polydispersity index (PDI). Analysis of variance showed a high coefficient of determination of 0.916 to 0.994, thus ensuring a satisfactory adjustment of the predicted prescription. The maximum predicted values of the optimal prescription were 91.62%, 14.20%, 183.3 nm, and 0.214 for EE, LD, size, and PDI, respectively, when HM amount was 1.8 mg and hydration volume was 9.6 mL. HM-loaded micelles were successfully characterized by Fourier-transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, and a fluorescence-quenching experiment. Sustained release of Lac-TPCS/HM reached 65.3% in 72 hours at pH 7.4, while free HM released about 99.7% under the same conditions.

Uptake and transport of a novel anticancer drug-delivery system: lactosyl-norcantharidin-associated N-trimethyl chitosan nanoparticles across intestinal Caco-2 cell monolayers.

In this paper, novel liver-targeting nanoparticles (NPs), lactosyl-norcantharidin (Lac-NCTD)-associated N-trimethyl chitosan (TMC) NPs (Lac-NCTD-TMC-NPs), were prepared using ionic cross-linkage. The physical properties, particle size, and encapsulation efficiency of the nanoparticles were then investigated. The continuous line of heterogeneous human epithelial colorectal adenocarcinoma cells (Caco-2) cell monolayer model was used to study the transport mechanism of Lac-NCTD, and the effects of factors such as time, temperature, pH level, drug concentration, enhancers, and inhibitors. This model was also used to indicate the differences among Lac-NCTD, Lac-NCTD-associated chitosan NPs (Lac-NCTD-CS-NPs), and Lac-NCTD-TMC- NPs in the absorption and transportation of membranes. Drug concentration levels were measured using high-performance liquid chromatography. Active transport and paracellular transport were suggested to be both the primary and secondary mechanisms for Lac-NCTD absorption, respectively. Lac-NCTD uptake and absorption were not controlled by pH levels, but were positively correlated to uptake time, and negatively correlated to temperature. The basolateral to apical apparent permeability coefficients (Papps) were higher than those of the apical to basolateral values. The inhibitor of P-glycoprotein and the multidrug resistance-associated protein 2 significantly enhanced the uptake amount of Lac-NCTD. Compared with Lac-NCTD, Lac-NCTD-CS-NPs and Lac-NCTD-TMC-NPs significantly enhanced drug absorption. Additionally, the latter exhibited stronger action. Lac-NCTD-NPs could penetrate the plasma membrane of Caco-2 cells and translocate into the cytoplasm and even into the nucleus. Nanoparticles were uptaken into Caco-2 cells through the endocytosis pathway.

N-trimethyl chitosan nanoparticle-encapsulated lactosyl-norcantharidin for liver cancer therapy with high targeting efficacy.

N-Trimethyl chitosan (TMC) was synthesized and used to prepare lactosyl-norcantharidin TMC nanoparticles (Lac-NCTD-TMC-NPs) using an ionic cross-linkage process. Lac-NCTD-TMC-NPs with an average particle size of 120.6 ± 1.7 nm were obtained, with an entrapment efficiency of 69.29% ± 0.76%, and a drug-loading amount of 9.1% ± 0.07%. The release of Lac-NCTD-TMC-NPs in vitro was investigated through a dialysis method, and its sustained effect was evident. In the human liver cancer cell line HepG2, the half-maximum inhibiting concentration (IC(50)) of TMC-encapsulated Lac-NCTD (Lac-NCTD-TMC-NPs) was only 24.2% that of free Lac-NCTD at 24 hours. Lac-NCTD induced HepG2 cell death by triggering apoptosis. In vitro cellular uptake and in vivo NIR fluorescence real-time imaging both indicated a high targeting efficacy. In comparison with Lac-NCTD and Lac-NCTD chitosan NPs (Lac-NCTD-CS-NPs ), Lac-NCTD-TMC-NPs had the strongest antitumor activity on the murine hepatocarcinoma 22 subcutaneous model. FROM THE CLINICAL EDITOR: In this article the preparation of N-trimethyl chitosan-encapsulated lactosyl-norcantharidin nanoparticles is described that displayed efficient targeting and sustained release in a hepatocarcinoma SC murine model.